The quality and cleanliness of endfaces of optical-fiber connectors represent important factors for achieving adequate system performance of optical communication networks. Indeed, any contamination of or damage on the mating surface of an optical-fiber connector may severely degrade signal integrity. Optical-fiber inspection microscopes are commonly employed to visually inspect and/or to analyze the optical-fiber endface of an optical-fiber connector at installation or during maintenance of optical communication networks, in order to verify the quality of the optical-fiber connection.
Because of the wide variety of optical-fiber connector types deployed in the telecommunication industry, optical-fiber inspection microscope probes are typically employed with interchangeable adapter tips so as to allow inspection of various types of optical-fiber connectors directly or as inserted in an optical-fiber connector adapter.
In order to appropriately image the optical-fiber endface, illumination light reflected from the endface should be appropriately captured by the inspection microscope. This typically necessitates that the imaging axis of the inspection microscope system be aligned perpendicularly to the inspected endface. However, this alignment can become impractical when inspecting an angled-polished physical-contact (APC) optical-fiber endface that is deeply recessed within a long and narrow optical-fiber connector adapter. An example of such a recessed endface is that of a E2000/APC connector and its corresponding connector adapter as shown in FIG. 1, as defined by international Standard associations (see IEC 61754-15:2009/COR1:2014 and TIA-604-16).
Some fiber inspection adapter tips exist in the art for imaging deeply recessed APC connector endfaces. For example, U.S. Pat. No. 8,976,345 to ZHOU et al. describes a fiber inspection adapter tip using a lens or lens system within the tip. The tip lens or lens system is tilted relative to the inspected angled-polished optical-fiber endface, i.e., the lens axis is not normal to the optical-fiber endface). The fiber inspection microscope probe is also tilted relative to both the tip lens or lens system and the optical-fiber endface.
Although there exist fiber inspection adapter tips in the art adapted to image deeply recessed APC connector endfaces, there is still room for alternative solutions and improvements.